The rate of tax would depend on the individual's circumstances.
Income tax is calculated in a fixed sequence. Non savings income first, then savings income and then dividend income. The rates of tax on interest are 20% and 40% and dividends 8.5%, 33.5% and 39.5%
Income Tax rates and Personal Allowances
We are unable to comment on the rates of tax that will apply. The fees charged by the investment company would not be included by your friend for tax purposes.